Conveyer system



f www5 Sept. 22, 1925,

- A. H. SHFFER comm-En sfsgmu Filed mayl g5,1 1925 MM @wwf Spt. 22, 1925. l

. A. H. SHAFFER CoNvEYER SYSTEM Filed May 25, 1923 14 Sheets-Sheet 2 @ff/Imn A. H. sil-LA FFEF:

CO-NVEYER SYSTEM Sept. 22,y 1925.

Filed may 25- 1923 14 Sheets-Sheet 5 sept. 22, 1925. 1,554,765A

A. H. SHAFFER -CONVEYER SYSTEM 'Filed May 25. 1923 14 Sheets-sheet v NT Semana, 1925.

' ,5554765 A. H. SHAFFER CONVEYER SYSTEM Filed May'a', 1923- 14 sheets-sheet 7 www A. H. SHAFFER GONYEYER SYSTEM Filed May-2.5, 1925 f 14 Sheng-sheet 9 Mil/W55 l ILM/aff Sept, 22, 1925. 1,554,765

A., H.. SHAFFER *C'ONVEYER SYSTEM Filed May 25, 1923 14 sheets-sheet 1o @vN /f\\ l Nl.; www, \`U, w

wsi r- Qw .QN 9% kvm;

sept. 2z, 1925. 1,554,765

A. H. SHAFFER CONVEYER SYSTEM.

Findlaw-25, 1925 14 Sheets-Sheet l l IIIIIIIl-II www Sept YZ2, 1925.

A. H. SHAFFER CONVEYER SYSTEM Filed May 25, 1923 1A Sheets-Sheet l 2 @2M/wiwi Sem.. zz, 1925. 1554,? 65

' A. H. SHAPE-'ER CONVEYER SYSTEM Filed May 25, 1925 14l sheets-sheet 14 Figure 12 is a. plan view of an electrical contacting device for opening and closing the swltch, with parts omitted.

Figure 13 is e. section of an electrical to show a loadmeleesing device with a trol` ley in position.

Figure 16 is e. section teken on line 1(516 of Figure 14, showing the releasing device inoperetve.

Figure 17 is a view similar to Figure 16, but with the releasing device operative.

Figure 13 isn detailed plan view ot a knoeko' device.

Figure 19 is a side view ol the knocked device.

Figure 20 is a sectional view taken on line 20-20 of Figure 18.

Fi lires, 21 and 22 are detailed views of a tro ley sorting rack.

Figure23 is a. transverse sectional view of a train shed, with distributing system installed and showing a movable delivery chute for delivering mail sacks into mail cer door.

Figure 24. is e side vievv of the trein shed shown in Figure 23. v 1n Figures 1 end 2 of the drawings, a typical layout of a track system is shown diegrammeticelly. The mail seeks are sorted and loaded at e distributing station, herein shown es e loading platform 10, sdjeeent one end oit e conveyer track section 1'1. The conveyor track is of the monorail type, as hereinafter more fully described, although other forms of track may be provided if desired.v A plurality of branch tracks 12, 12 connect with the track 11 at suitable intervals by means of switches 13, 13. In the system shown, the track 11 forms n main line, and the tracks 12, 12 'form branch lines extending" along the rziilvvay track platforms 15a, 15a, and having thereon.

various distribution points, es for example, at doors 14, lot' mail cars 15, 15 placed at certain points in the railway station. The conveyer"carriages comprise a plurality oi wheeled devices movable along the conveyer trucks, as for instance, e. plurality ot trolleys 20, 20. These trolleys each comprise a henger 21, orined of a single inverted U- shaped piece 21E'endpijovided ivitli ,a single flanged Wheel 22. A hook member' 23 deper ls `from one side of the hanger, and is adapted to engage and support the load,

Y vhchin the present instance is e mail sack 34, Means are provided for releasing the the hook member 23 on tlielienger 21.

lhook member is normally held in Lposition to load which consists in pivotally mounting Said memes 'a engage the load by a locking arm 25, plv* otally mounted at 27 to move on an 'axis transverse to the pivoted hook23, and provided at its lower end with a ydetent- 26 adapted to engage said hook. A projection 23 on the upper cud oi locking arm 25 is adapted to conci with suitable tripping oi' actuating` devices 110, 110 placed :it the various distribution points in the system, as will hereinafter be more fully described. vhen the dctent 2b is disengaged, the hook 23 is free to swing downwardly and release its load by gravity.

Means are provided for propelling the trolleys together with their load along the various tracks ot' the system. 1n thc form shown, the propelling means comprises a plurality olf endless conveyors 29,' 29g-30 haviingr portions thereof mounted to move along the various trucks, und provided with projecting members adapted to engage the trolleys. The conveyors shown are of the chain type, but any liexible conveyer device may be used tor the purpose. Vlhe convey'ers 2S) and 29, along the main line 11 comprise a series of ordinary linksI 31, 31. Other links 32, provided with means for engaging the trolleys, nre spaced at equal intervals along the chain. The conveyors are trained over suitable driving sprockets 35, 35 and idler sprockets 36, 36, mounted in any suitable manner, and driven by power, as'ior instance-bymotors 35, 35. In Figure 2 it will be seen that conveyer 29 extendsv along an inclined portion 33 of the main track 11, and isjconveniently trained over sprockets rotatable on longitudinal axes. Another conveyor 29?l extends along e substantially level portion 3410ic ysaid main track 11 and is trainedovei"spi'ockets v`o" tatable on vertical axes.

The trolley engaging members on the main line conveyers 29 and 29a comprise pushing fingers 32?, 32, projecting downwardly from links 32, 32 of the chain, and provided with rollers 32", 32b extending into position to engage the rear surfaces of the trolley wheels 22, 22, and tting -betvveen the flanges 22 22'. 4there'oiC just abovethe axes ci' seid wheels. These engaging members are arranged to permit the trolleys to pass freely oli" the mein line 11 when oneof the switches 13` is opened for passage toy a branch line 12.

The conveyors 30, 30 for movingy the trolleys along the brauch tracks 12, 12 may be arranged and driven in the same manner as the conveyers, on the main line 11. 'The branch yconveyers, however, are provided with a different type ol engaging men bers' v:nn-ing ihn proper while moving along lhe innin sind l 'oncl'i vided nl its lower end with forwardly extending pin 4.0 adapted lo engage bcnendi the upper cross bnr /l-l on the trolley li-(inner. fifhinggfed lockingA nicnibcr lf2 connected nl lhc forward end` of iille .nienibcr il?, :1nd nrrnnged to be swung' remfnxnrdlly by conl'zict willi llie cross'lnir L So ne lo permit the loller lo pass over the pin lll) when, thc finger ll is moved lioirnrd the trollcy. :is indicated in llignre Ll, in which position die lrolley is retained on ,the pin li). lly menne of this oonstrucion lie lzrolley is zintoinnlicnlly connected to one of the links 3S) on n. branch line conveyor 30 soon :is the irolley is Switched onto n ln'ancli'line lll and .is picked up by one of the trolley engaging n'ieinncrs 37.

'll'ie 'po lions oli the conveyers intermedi# nte their neeocinled Sprockels are movably euiiporled by suitable means adjacent the fraiche. nn 'for eXnrnplev-lie spaced chain links; 32, o' llicconveycrs E29 and 29a, ne well cernin other links ol the chain, nre provided with arms 5l), 50 extending lnernlly from lille lop of said linke and niorobly snpporled on n pair of 'rails 5l, 5l, wliii'el'l in the forni nlio'irn comprise oppo- Silely disposied channel bnro. These channel bern nre arranged on opposile sid-es ol die Krolley milfs 1L sind the lower flanges 51a, 5l lliercol" exend imvsirdly ino position fro forni lznrrnl bcnringrn 'lor 'lie lzrollcjm. Flnilnbliiiczir'ngg nwzrns 'lor l'lc arms 5d 50 :ire provided. lor eKninplc. libre blocks: .32. 52 nrc sccnrcd llo lhe nndcr inrcn ol llicsc uriney no :is to provide :1 in'nctirnlly noiscless' :inil'riclion bearing lor lille rlrnin. 'lhe rniln 5L nl und, rollcy lrnck ll :irezdl sup porl'cd on hangers; 53, 5? nl siiilnliln inl'crvon. This rctnrn or inwardly moving llehln oll ille conveyor nro not nfssooizfiled "will: n trolley rnrk, but muy also bc eenpporlfd il' desired on rnd scifiions 57i. .'35

ronnnrcd lo lningcrs 5l. 5lns slion'n in Figure 10. The conveyors lll). CSO nrosnp porti-,d adjacent the branch tracks l2. .lil in u similar manner.

ll, desirable to provide menno for insplicing of the. trolleyn lines. Af; before Stated thc n'min linr conrcyere fill :ind have n pluralityY ol' spliced trolley enlfnging members 32', 32. und :i device is provided on lhe s vnliein lor pon milling bnl one trollej,T 'at n time to -iio ndniillcd on lille line lor ei'igrogemci'lt will] Said conveyor'i'nmnbcrm This device is proffernlily located nl the Shirt/ing end of Cloe lirst conve/ rer 2l). :is indicated :it 60.111 llignres 1 und Details of this device are shown in liligrures (l sind 'i'.

The idler sprocllzet l-xat the lower end nl the inclined conrveyer 29 is keyed on n shalt (ll having bearing" in a journal k eik This journal may be movable longitudinally on llic Sup'prn'ling;l lruinc (lil :1nd ndincd by lhrnndcd ineinbcrry li-l. (ll. lo conro'l the lcnnion ol llic ronrcnrcr rhnin. (Sfr is licycd on lhc slinll lll. :1nd ik.' nicshei'l n'li'h :i geur 6G on stnb Hhnl'l 6T. il. reciprocating' linl: nl# is; connected lo gear (lll by :in ccccntric dcvirc. Sncli ns' n cnin (il rot-nt- :ibln willi said geni' :ind having engagement willi n paiir olf' opposiicly disposed friction rollnrs l0. T() carried on llic linl; (lll. 'l'liies` linl; is jironlly conncctrd with n lcrcr :irni' 71 .on n rocking` shalt T rnid shnft is ISupported on die benin Til by Suitable incline,` :n for inelnnce n clnrnp Tl :ind bolts T5. 75, feo ns lo be longindinnlly fidjnslzililc nlon; mid beam with thc sprocket ll und ilsv :insocinlted parte. .l pair olAl opi'ifisilcl)r disposed nrnisf, 7G :irc i'i'iounicd on 'dic rockin;r Shaft Ti -:ind are nach pirol'nllv Conner-lcd will] n downnirdliv (,Xlcndin'gf rod '77. Slidoblc in siiilgnlilc guides '755. TH on the clamp. il, pair of spzicinl lingers T). Tf) nre connected to lbe bottoni @nds of the rods T7, 'Il'. lt Will be seen lhn'r these lingers; will bc given vertical reciprocnblc movcment in opposite directions; when lelie .nlnilit 72 in 'rockedfflnd Said lingers nre cncli arranged with respect to the trolley rnil ll. 0 as lo engage the nppnr cross bnr ll of l'he trollo). 2() on Suid rnil in :ill posilionn ol' snid lingrcrn` excepting llirir cxrcnic uppermost positions. Huid linrg'cr.- :irc also 'Ilpnccd l'ronl cach other so, :in lo :idniii bnlV n singlyl'rollcyv nl. :i linlc lwlrrccn llirni. :in indirnl'cd in floll'cd lines in lfi'lnlin'c ll. lli' mennol nlEl thinI :ii-rangoninnl. n plurnlily ol' lrollcyn ill.. 2l) n niy be loaded on lille inclined lo.idiin lrnf'li sci-tion l l :nljnccnl the loading plntzl'orni lll. :ind ull lrollcyn will nn'n'c l ";'1n,vil1y until llicy cnll'ng'c rbc neuroni; lingfcr '[9 o'l l'lwepncing dcvicc lll). nlnre llicy will lic sloppcd. s this linger is rninild lo ils nppcrniorzi position. onu lrfgllliv nini' puns'. nndcr il;n bnl: will be ntoppcld by the ywond linger. which in then nl. il lower-:noni position. The. movement `ol' snif! linnrrs is then rcvcwrd `until the second linger in nl ils topinosl' poninion 'when 'che trolley is rclensed and permitted llo poss on down the inclined rnil into position lio be pirlced up by one olthc pushing und {Ienrinn connection is nrrnnged lo ln, driven in timed rolntion 'willi thc crmx'efver clinin 2l) no :in lo puso but one trolley Yl'oi anch pushing linger 'lill. i

lll portions; ol1v llie s rsl'en'i where the trollebY is not propelled by n'comf'ever, it in denimble lo provide :in incline for the trolley to proceed by ernviy :dong the truck. For example, Where die trolley pnnseS vfrom the main line l1 lo n branch line 1:2, jche trolley leaves the n'iein line conveyer 2W, and muet pass over the switch 13 before it .is picked up by :i branch line conveyor 30. 1li this *point the portions of track intermediate the 4ll5 lingers 32 on the' ronreycr Q9. 'lhei com adjacent fonveyers 29 and 3() are downj-.mrdly inclined, this port-ion including the switch track 8l and the adjoining curved track sections S2, 82 leading into the branch lines l2, l2 as shown in plan view in Figure Vl and iu prolile iii Figures 3 and 4i. These inclined track portions are preferably provided willi sullic'ient slope to produce a minu iinuni speed o'l a trolley equal to the. rate ot' nioveinent ot the conveyors, -for otherwise the desired spaced relation of succeediiie: trolleys set up by the spacing device 69 may be disturbed. with detrimental effect on the smooth and eliicient operation of the system. Similar inclined portions may be interposed between succeeding convcyeis on the saine line, as 'tor instance, the portion indicated at S3 between. conveyers 29 and 29 on nain line ll.

YEach of the trolleys is provided with means adapted to coact selectively with the various switches 13, i3, so as to be directed automatically to a predetermined branch line 1Q. The trolleys are further provided with means adapted to coact selectively with the various releasing devices preferably located on branch lines l2, 12.

rllie switches4 13,13 and the selective means on the trolleys :tor operatingsaid switches will now be described. ln the form shown the switches are electrically operated, and each includes a pair of oppositely acting` ,solenoids d5 and 86 having an' armature 8T operatively .connected with the pivoted i switch track section 8l.

The. solenoids are electiicallyoperated from a suitable source, and adapted to be energized through' contacting devices 88 and S9, respectively. One 'contactingl device 88, connected in circuit with solenoid for openingl the switch, is positioned adjacent the'main line. track il, as indicated in Figure l, in advance or" its respective switch. rlhis contacting device may be oi any suitable forni, as for instance, a longitudinal shoe 90 connected by a pair Aof parallel links 90a, 99E to a traine 91. The

. shoe is normally held outwardly by a spring 92, but when moved inwardly it closes a circuit through contacts 99", 90', and the solenoid 85. The shoe 90 is arranged at a certain height/so as 'tocpntact with -a 'proljection 98 on one'side of the trolley hanger. It ismaiiifest that selective operation of the var'ioiis switches will be adorded by providing; a certain position ol the coacting trolley and switch contacting` members diierent from the positions oi' similar members on all other switches in the system. y A second contactingr device similar to that inst described is placed on the branch'line lpist beyond the switch point, as shown in igure l. This contacter is in circuit with 'solenoid 8G for closing the switch after the trolley has passed therover, the arrange ment being such that the mainline 11 is norweaves on a pin 97. Said pin is connected to the armature core 87 by means of a piece 97, made of brass or similar non-niagnetic material, which forms a continuation ot said armature and is slidaloly mounted there* with in the solenoids as shown. An operating` arm 98 is pivotally connected at one end to the switch 'track portion 8l, and has at its opposite end ayoke 99 ex'tendingover the outer locking disc 96.. The locking discs and 96 are provided with spindles 95a and 96a respectively which are telescopically engaged respective to each other, and when connected as shown, entend through an aperture formed in a downwardly extending piece 99' integral with yoke 99. A compres-v sion spring 95b is inserted on the .spindles intermediate disc 95 and yoke piece 99, and

.outerV disc 96 is engaged on its outer tace by pawl 96"', and on its inner iaceby pawl 95",

and thus is securely locked against Inoveinent in either direction.` The spring 96h is undercoinpression, tending to maintain the yoke "99, connected through arm 98 to the switch track 81, :firmly in closed position with said track in alignment with the branch I trackll. To unlock the parts and throw the switch in the 'opposite direction the solenoid 86 is energized' as for instance, by passage ofthe trolley over the contactor 88 on-tlie branch line 12. The armature 87 will be 'moved by'"^magnetic :torce in the direction to throw the switch. .The initial movement I y ofthe armatureserves to partiallyinpress the spring 95.' A lock releasing member 96i is' mounted 'beyond disc 96onthe pin 97 vwhich has been described as being connected tov the armature` 87, and extending through the discs 95 and 96. This lock' releasing member is moved with said pin and armature until't enga es a cam 96 on the lock-Y ing pawl 96, an raises thevlatter, thereby ne; i

` disc 9".

113 provided 'w1 um l0, in which lie switch imams. il i:lsiiiiffl is in aligiinmn with iii/c, mais lim wick Ei. This movismei Causes dus locliii'igf zzwls 95S and 9 c $0 engage lis sfracund lacking (lisci 95, lie ineria of ii s mm'musnt, heini: siifiicien to partinliy coiiipiess spying' 05h lieii's the paris iii-:coms lucha-fi. Remi-ss s'ipsraitiim 0i the switch i. ii'sl described, fiofsiiion is proi'iucmii in i@ similar nieuwe?? the. piiwl e being milcieirl in 4'ibis insignias by fi loin-lf i'elezisingme'musi' Q55 mi pin lli", afijscsii;

The means for sswivsly iactiizzingi; lli@ release msclizsnis mi the mllsys 'viii lo@ flescl'iisi'l. A. gli iiiilijy @if sasl.; i'QLzisig' devies il@ il@ are psi'ieiiisd ed soins in ills sysiemr, -iisisml ly mi iii@ in'imch lins l2, lf2. En. i levies minimis-s an falesia-imi mnieiiiiig (ifs/vies lll 'riisjgo'ilsivs a in'Qlesirnisci aimais' man? if u projevcirm El@ on om? mi lli-s html sys fill im@ :iclnpvfi wlmi closed *Ui energize s. solsmiicl "tix am auiiizizii'@ ll-Ll mmralile im@ *Ulis pzi''h @if ills pi'oieciimx liicliiiigf Win25 lon 'the Holley, liz lli@ slm wtlis conaciing device 00min-isos a loiigiiivsii nal slm@ ll conm-)cisti by ii 'pail' mi viiziiiilsl links 116., il@ is :i Timms The simi,

by ammnging lzlie sims al, s 'mwaiii lieigii jf Canet with piojscimii li@ mi the inilsy bmw-si lli-Yiwu tlm sims is illus engaged ,through :i piiii of minimis 'lilik U9 mmmlie sslsnoifl ll'L also iiioimisfi im the i3 wie. A spying 123 smimcsel lo ilw mimi" @mi of iis ammini@ li? miling' maintain the iai'ei .in isxzicsl 'gmsiinn in ille ssii rloid casing i724., as Simwii in liigiiil. Currentl is supplisd lo tha Circuit Clu'migii Cmiductms :md ll siiiisclsii 'is iii@ solenoifl and rms gif iii@ @mit U9. respectively. The imm@ il? @ii which lili@ enir@ Coni-raming 'flwifcs is mouiiizsi, i inomlily Connects-fl 0 a suil'iiis mil. sf'ifiing ainnggsiiie track fail l2 iilis l'i'z'lclf iiiimiis 53? "lii i'iwtioii iii@ 'fimiis compris Csm iiiemlim pimisfi mi die frame and ops iililv lijv4 :a liii'mliv 1532 lo sngagv ills 0mm" side 01'? rail '1'30 slim@ zi flange i3()a thereon. The cani member Bl may be partially re- @humping ELS leased, as shown in full lines in liguif@ l5, 'in which position tim @smashing device 11G suppoi'lsd ifm' moi/ement bodily :along the 'uil flange l-lif'f tlms aiivwiiiing mi-ions :icljiisiiiwiis slsnpfilis brunch limi 12, depending spun im ifslzilive gmsitisn wf the mail cui' limilin wiiic'i i is desired im Cisliver the load. Tim Qlectii :nl cmifiuiois 125 :mal-

eii@ in lli@ 'form mi* ii Flexible cable t0 pei'- Imt smrli adjusmn. 'lim clamping: msm-V hay ll mii? also ly@ moved 'ii sitiniii'z@ fully simili lili@ critzicting @levies ilis mil )l-30 :is slimvn 'im diitte lines in i. igiim l5. Tlis viiimzs contiicing flev'ices 31% fheili' iiiibieiislizimg'siiliie to vir iimis @ms 0E siis siem, and for this piu'- psse 'die lsfiibls supply ciiznls 133 is pmviiei Willi :i iisiaclizilils plugilflfl of the usual. type, cmiiiscible to viii-illus sscles l imls along is :onduil:

93 sin@ Wiiisli cooperate rsspectivsly wil-,li iii@ svrii'iches and load ,ielsssmg devises 'lml muy ais miiiiigsi m various posi irms on lili/s hanger lo moslims :i 'Wide 'fangs :if sslsciv@ combinations; For lah@ mllays lufi'isi-mm'o il? is 4obvious that eL-Mausi as well :is lli@ wanting sind ll @n lli@ switches :mtl irs- ,i'icss zsspsciivsly, iiay lis adjust- "i" (issiiefL limi .tlis putpss of illusswinging of lie istie?. als@ piovifle ai nm'sl form Gl" :huis ily which ille maii sinks may iis iosiflmi directly ist() 'li .,i:zirs-.l-5 i5. 'lliis devise Qfiiiipiisisi @imite 1537 l'iziving am s'rm slifinuly connects-fl, i@ ai `mil 1,39 silemliug airing lli@ train iliitioriii outside m? the wiveyer tinck 1:2. The lower @mi of tile finite is to iis siifung iniio and out iii iii@ om' filmins shown in Figuera' 232 A. pivulscl limes 1139 Comiizcsd in lie lows? @mi of lli@ sluit@ imfi piiiviiisd Wia' pf@ jcclimi .35 :it i's; miic? emi, zilapsfi wiisii in position cngagfe lie edv@ ofthe tizim, plzitmiii so to hold ills simili@ in dieras sited posil'ifiii, shown in li gum 23%. when :5 in use 'lle limes i539 may lie oldscl up lll() @y enseres laterally away from the car so as not to intertere with the passage of passengers 'or station vehicles along' the edge et the plattorni,

scribed. This device is designed to automatically disconnect the trolleys from the branch line conveyers 30, 30, after the load has been released trom said trolleys and the vlatter have been carried, empty, beyond the l end ot' the branch track endreturned along the incoming flight of said conveyer to a4 point convenient to return said trolley to the distribution point for another outgoing journey. T his knock-ott device is therefore preferably located adjacent the main line track 1l, in position to drop the trolleys on. an independent conveyer of minimum length for return to the sorting1 and distribin4 tion station, although under some conditions it may be more advantageously located at other points alongf the return flight of conveyer i are adapted to be connected to the conveyer by means ot a Yforwardly extending 'pin 40 ot` a trolley engagingr member 3T, with a hinged member 42 closingr the front end oit said pin. The knock-ott device "for separating the trolleys "from this connection is shown in detail in Figures lil, lil and 2O and comprises lever 140 pivotally mounted on a suitable bracket lill connected to the return flight supporting rails 55. A pusher ,lever '142.,shorter than the first lever is Vpivotally mounted on a projecting bracket 'Iletl and off setin the direction ot' movement. ot the conveyer chain. The pusher lever M2 is slideably connected to the lever 140 by a pin 141i on the latter'worlring in a slot le'l.

in the former. The lever 140 is arranged to extend into the path ot movement ot the trolley engaging .members 37, 3T. as they carry theltrolleysfalong. Said lever first engages the pivoted piece 42 atthe forward ind ot the connect-ingr members S7. so as to swing the latter upuf'a-rdly` as shown in Figure l). hislever is then moved pivotally by the connecting member 37, and the shorter lever moved at a greater rate than the longer lever, .owing to their cooperative errungement as shown. The outer end of the short-- er lever 142 thus engages the rear oi the trolley. and moves it lforwardly ot the pin 40. Ilhe trolley is thus knocked oil the conveyer, and-may drop by gravity to a conveyer tor return to the distributing' point. or loadingT platform. The levers l40 and 142 are returned to operative position by suitable means such as a lever 146, loc-ated beyond said first named lever, and, pivotally mounted intermediate its ends on a bracket 1475*. link 1.47 is pivotally connected between the outer end el lever 146 and im s before described. the trolleysl 142 is caused to be Jforwardlyintermediate point 148 of lever 140, The a1'- rangement ,is such that the outer end 140a of lever 146 is moved into the path of a trolley engaging member 37 bythe same movement which disconnects a trolley from said engaging; member.' Said last named lever is then engaged and moved by the member 37, which movement is transmitted through link 147 to return the levers 140 and 142 to their operative positions, as shown 75 in full lines in Figure 18. 'c f vAny form of conveying device, independent of the main conveying system, may be used for returning the trolleys to the distribution point, as for instance, a gravity conveyor 1,50 may be used advantageously,

as shown in Figure 3,: when` the knock-oft1 is relatively near the distribution station, or a belt conveyer 151 such as shown in Figure 4, may be preferable where the knock-off de- 8f' vice is at a considerable distance from the distributing. station. i,

lWhen the trolleys are returned to the disi tributingr station, they may be sorted and arranged for further use. For this purpose it is desirable to provide sorting racks 155, 155 as shown in Figures 21 and 22, adjacentthe loading rail, for convenience in picking eut a trolley provided with the desiredV combination tor carrying the sack to its proper destination. Thisrack comprises a series ot parallel rail portions 156, 156, on which thel trolleys may be arranged according to their respective destinations. The use and operation of the distributing system Will be sufficiently understood by thoseislrilled in the art from the.above description.

Although l have shown and described one form in which my invention may he embodied, it will be understood that the specific construction of the various parts and defvices of the system may vary Widely from those. herein shown and described without departing,Y from the scope of my invention. For instance, electrical devices have been shown as a preferred torni' of switch and load releasing means, but so far as the broader JFeatures of the invention are concerned, mechanically vactuated devices might be utilined, it desired. l do not therefore wish to 1 5 be understood as limitingr myself to the specific details of mechanisms shown and described, excepting in so far as specifically defined in the appended claims. l claim as'niy invention: l. In a conveyer system, in combination with a trolley, a length of track for supportingy said trolley, means movable along said track connectihle -With said trolley for r propelling the same, said means extending 12" beyond said track and adapted to carry said trolley independent of said track during a 1 portion of its movement.

2. ln ay conv'eyer system, in'-combination with a trolley, a length of track for sup- 

